Foot odor and infections are common problems associated with microbial growth in the enclosed environment of a shoe. Moisture resulting from foot perspiration provides an ideal growth environment for both bacteria and fungus causing odor and athlete's foot, respectively.
The inhibition of such microbial growth has been a long sought goal of the shoe industry, and numerous approaches have been proposed and tried. Commonly, activated carbon is incorporated into a shoe insole in an effort to absorb odors and moisture. Although partly effective in controlling odor, the degree of moisture absorption is not sufficient to inhibit microbial growth in most cases. Thus, the odor continues to be produced and athlete's feet and other infections can occur. Moreover, the ability of the activated carbon to absorb odor is quite limited and the effectiveness of the insole is usually short lived.
Antimicrobial agents have also been incorporated within a shoe insole with varying degrees of success. Usually, however, the antimicrobial agents are either released too rapidly to provide for long-term effectiveness or entrapped too securely within the insole to provide for sufficient activity.
In view of the above, there have been a number of approaches for deodorizing shoes. For example, a U.S. Pat. No. 4,776,110 of Shiang discloses an insole-ventilating shoe including an insole having an air pumping device formed on a rear portion of the insole. The insole has an inner guide protruding upwardly to exchange fresh air outside of the shoe vamp, and plural ventilating grooves with through holes formed on a front portion of the insole for circulating air from the pumping device in the insole and shoe for comforting an individual's foot.
A more recent U.S. Pat. No. 5,010,661 of Chu discloses a unidirectional airflow ventilating shoe and a unidirectional airflow ventilating insole for shoes. As disclosed, a unidirectional airflow ventilating shoe having an ordinary upper and sole. A unidirectional airflow ventilating layer (1) is provided on the sole inside the shoe. The ventilating layer has a compressible cavity (2), air inlet (3), main airflow passage (4), branches (5) and air outlets (6). Fresh air outside the shoe is unidirectionally sucked into the ventilating layer and blown out to a fore part inside the shoe.
For convenience sake, a unidirectional airflow ventilating insole can be made for any kind of shoes. The insole comprises an upper portion (7) and lower portion (8). The structure and shape of the upper portion is the same as that of the ventilating layer (1). Lower portion (8) can either form an entirety with upper portion (7), or be an elastic substrate adhered to the bottom surface of the upper portion with adhesives. The insole can be used in any kind of shoes and attain the same result as unidirectional airflow ventilating shoes.
Finally, a U.S. Pat. No. 6,227,458 of Dever et al. discloses a deodorizer for masking foot and shoe odors through controlled release of fragrance and which utilizes releasable interlocking surfaces for retaining the deodorizer in contact with the shoe.
Notwithstanding the above it is presently believed that there is a need and a potential commercial market for a ventilating shoe that includes a removable deodorant and/or perfumed pad. There should be a demand because such shoes incorporate a removable pad that can be easily and readily replaced with a relatively inexpensive insole that contains a deodorant and/or perfume pad. In addition, the shoes contain a unique ventilating structure that helps to aerate the shoe to reduce moisture and odor together with an air cushion under the insole. Further, it is desirable to provide a convenient deodorizer for masking foot and shoe odors in which the perfume component can be easily applied to and removed from the shoe interior, is comfortable to use and incorporates a unique valve arrangement that allows air to be drawn into the shoe and at the same time tends to resist the outflow of air through such inlets.